Given that blood has a density of about 1035 kg/m3 determine the blood pressure of this poor, unfortunate horse.In December I laid a common Field Gate on the Ground, with some Straw upon it, on which a white Mare was cast on her right Side, and in that Posture bound fast to the Gate; she was fourteen Hands and three Inches high [150 cm]; lean, tho' not to a great Degree, and about ten or twelve Years old. This and the above-mentioned Horse and Mare were to have been killed, as being unfit for Service ….
Then laying bare the left Carotid Artery, I fixed to it towards the Heart the Brass Pipe, and to that the Wind-Pipe of a Goose; to the other End of which a Glass Tube was fixed, which was twelve Feet nine Inches long [388 cm]. The Design of using the Wind-Pipe was by its Pliancy to prevent the Inconveniencies [sic] that might happen when the Mare struggled; if the Tube had been immediately fixed to the Artery, without the Intervention of this pliant Pipe.
There had been lost before the Tube was fixed to the Artery, about seventy cubick Inches of Blood [1.15 L]. The Blood rose in the Tube in the same manner as in the Case of the two former Horses, till it reached to nine Feet six Inches Height [290 cm]. I then took away the Tube from the Artery, and let out by Measure sixty cubick Inches of Blood [0.98 L], and then immediately replaced the Tube to see how high the Blood would rise in it after each Evacuation; this was repeated several times, till the Mare expired ….